UNDERSTANDING NON-LINEAR
JUNCTION DETECTION

 

UPDATED FOR 1999

The Detection Of Active And Non-Active Eavesdropping Devices Buried In
Walls And Furniture

By Ralph D. Thomas

 

 

A Photo Of Orion: The Non-Linear Junction Detector

 

 

UNDERSTANDING NON-LINEAR JUNCTION DETECTION

The Detection Of Active And Non-Active Eavesdropping Devices Buried In Walls And Furniture

 

For those really serious about countermeasures services in the area of corporate, professional and business accounts, clients are demanding a high level of sweeping services. One of the things that they frequently want to know about is if the service can determine if there are any hidden eavesdropping devises hidden inside walls and furniture. There is a technique known as non-linear junction detection that will, with the right equipment and training, help you detect eavesdropping devices inside walls and furniture even if the device is not operating. Non-Linear Junction Detectors are detectors that look something like a metal detector and will detect various types of items inside walls or furniture. The idea, of course; is to be able to detect the inside of a wall or inside furniture for hidden eavesdropping devises without tearing them apart.

 

The use of a Non-Linear Junction Detector is dependent on the fact that electronic devices and metallic objects that come in contact with one another create what is commonly called a non-linear junction. That is, any two components that touch each other will produce a non-linear junction. What a non-linear junction detector does is detect these non-linear junctions. In doing so, active or inactive, working or non-working eavesdropping equipment such as bugs, microphones, tape recorders and other listening devices hidden in walls or furniture can be detected.

 

What a non-Linear Junction Detector does is sends out a radiated signal and then reads a harmonic frequency level that is a return of the signal sent out. In effect, you are reading bounce-backs. In effect then, a non-linear junction detector sends out a microwave signal that penetrates walls and then picks up a reflected signal that bounces back. With the better models, various forms of analysis can be made of the reflected signals coming back to the unit. There will, of course, be many things inside of walls and furniture that will produce natural non-threatening non-linear junctions. For example, springs inside a chair that make contact with a screw head or nails making contact with other metallic objects inside a wall will produce a reading. However, proper analysis can be made with the right kind of gear.

 

It's important to understand that the two functions of a sweep using Non Linear Junction Detectors are:

 

1) The Detection Of Non-Linear Junctions.

2) The Discrimination between junctions between electronics and other junctions

 

Without the second, the sweep is simply useless because their is just too many other objects that are causing the readings.

 

So how does one use a Non-Linear Junction Detector for Discrimination.

 

 

Photos Of The Graphics On Orion. The bar graph on the left is the strength
level of the equipment. Note the difference in the
junction readings on the graphics for harmonics two and three.

HARMONIC RETURNS AND READINGS

Harmonic returns that are not electronics are not well defined. Electronics are well defined. Electronics will have a strong second harmonic signal and a weak third harmonic signal. A false junction will have a weak second harmonic signal and a strong third signal.

 

The new Orion Non-Linear Junction Detector has extremely good isolation of second and third harmonic signals which come up on a visual bar graph. It is important that the two harmonic signals mentioned do not interfere with each other and that's exactly how the Orion was made to work.

DEMODULATED AUDIO

Noise Spikes: On an actual junction, the noise level will decrease as you approach the object and increase as you move away. Audio will be at it's lowest level directly in front and/or over the object. It will be the highest just off the object on both sides.

Vibration Listening: Upon hitting a junction, you can hit the wall with your fist or a rubber hammer which causes a vibration. This vibration will cause the demodulated audio to change. On a false junction (non-electronic) the vibration will produce a cracking sound. On a real junction, silence is golden.

Tuning In: With good detectors you can sometimes hear audio from some tape recorder heads. On many video chip cameras you can pick up the video synchronization pulse noise.

 

Side equipment that should be part of any non-linear junction detector would be a a flexible fiberscope or borescope, metal detectors, dental mirrors, stud finding equipment, soft hammers, flash lights and maybe even xray equipment.

CLICK HERE TO REVIEW ORION: THE NON-LINEAR JUNCTION DETECTOR AND THE TOOL KIT THAT GOES WITH IT

 

TAKE A TOUR OF THE ORION RIGHT NOW

 

 

 

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